IMS Replacement - to lock or not to lock the cams

Getting ready to replace the IMS on my 2001 Carrera Cabriolet. Got the new bearing, the LN tool kit, and everything ready to go. I have read conflicting information about loosening the chain tensioners and locking the camshafts. Some people perform the procedure with and some without this process. How is it possible to do this while the engine is in the vehicle? Also, and please forgive my ignorance on this, how do I find TDC on Cylinder 1 with the engine still in the car? Thanks in advance!

In case you are not aware, the official instruction is available here http://lnengineering.com/files/IMSR-...n-Warranty.pdf

So not really an option Lock em with the correct tool

Thank you, I had not seen this before! Thank you!

BTW, also cross check with this excellent illustration with photos and explanation. http://europeanpartssolution.com/wp-...structions.pdf I think this is in agreement with LN's instruction but please double check (ignore the torque specs, which are for the roller bearing).

To note: At the end of this procedure, they forget to mention to reinstall the 2 chain tensioners they removed at the beginning of the procedure: pp 3 & 4.

Quotes source post: 12364747

Good catch! Hopefully you check your work bench for leftover parts before starting the engine

This video should be pretty helpful in regards to your question. Believe it's about 1:20 in. Here is a good IMS bearing DIY that may help you with the process as well. -Luccia

To the OP, I've read stories of timing jump when ppl follow the Pelican DIY on IMSB, which does not suggest locking the engine at TDC nor locking the cams. No offence Luccia as Pelican has plenty of high quality DIY articles but this one is truly questionable.

Thanks to you all for your helpful input and links. The problem I have is that it seems to me like they're based on having the engine removed from the vehicle. I might be wrong, but I looked at the lower plugs to plug in the cam locks before removing the chain tensioners. There is a portion of the car's frame about 1" away. How on earth would I fit the cam locks in that small space? Also, does anyone know how to check whether it's a 5 chain or a 3 chain engine? Thank you!!

2001 = 5-chain and you need to lock the bank 1 (left side of car) cam ends at the water pump side.

I couldn't do this without you all, I really appreciate your guidance!!!

1- Lock crankshaft to TDC (pinned) 2- Remove cam end plugs 3- Lock cams 4- Remove tensioners completely 5- Remove IMSB flange 6- Extract IMS Bearing

Quotes source post: 12365147

Well, that is news to us. Thanks, I'll be sure to pass along the info. Regardless, the video I posted is definitely a great one to follow. -Luccia

Luccia, It is not news to Pelican or Wayne !!! Just ask Wayne.He graciously corrected himself on this issue recently. http://forums.pelicanparts.com/boxst...placement.html JFP & I had this exact discussion with Wayne on your own Pelican Forum recently. Check posts by "Scnell Gelb" & JFP on your Forum. The reason the Pelican procedure is wrong -it was originally written long ago when parts were difficult to obtain/expensive and there was less knowledge available. Use the LN Instructions linked by Ahsai because failure to lock the cams can cause very expensive & totally needless damage.Pelican sell the cam lock tools -for a reason.

Quotes source post: 12367378

I've been in discussion with Ahsai about this. Nick, here at Pelican, pointed out the cams should be locked with a tool in a comment below the article, but it was never updated in the article itself. We actually have a very knowledgeable Porsche tech in house now and I am having him review it to fix/update the information that is needed. I don't speak to Wayne often so I appreciate Ahsai pointing this information out to me so I can get it properly updated. I definitely don't want anyone to feel misguided by our tech articles so, again, I appreciate the input! -Luccia

You are welcome. If Wayne is hard to reach, just ask us here ! You really can't be expected to know all this mind-numbing,arcane detail -but Ahsai seems too !

Whoa folks, I think I just saw my AOS from below! Is that possible? Is it possible to reach and replace the AOS from below while I perform the clutch and IMS replacement? That would be a huge breakthrough since I noticed occasional white smoke at startup, and with 126,000 miles I want to replace the AOS. Again, all of you have shared priceless information, THANK YOU ALL !!!

Quotes source post: 12367777

If you see me roaming around or have suggestions on anything definitely reach out and let me know. Wayne is a pretty busy man so that is why we are here! -Luccia

Quotes source post: 12368586

It is against Internet Law and Forum protocol to post a question that has nothing to do with the original topic! As a side note: if you're in there then do it. I've heard the main problem is getting the hoses disconnected from the AOS, but if you can wiggle your hand up there to pinch the connectors you are home free.

Quotes source post: 12369179

Alright - Internet laws and Forum Protocol noted. My apologies... Thank you for the additional info.

Quotes source post: 12365147

Hi everyone. As I mentioned in the threads on Pelican, I have not heard from anyone who has had issues with the timing jumping after reading our article. After I pressed some people who claimed this, they admitted that they just had people who screwed it up and had *assumed* that they had read the article. If you follow the procedures carefully, it works fine and you shouldn't have any problems. I also insist that you check the timing when you're done just to make sure that you didn't make any mistakes. Having said that, I added the following note to the article on March 16, 2015: Unfortunately, I just checked the website, and it would appear that this correction did not get incorporated into our new page update (they must have pulled the data prior to me posting the update), so that info has been missing for the past month or so. I will instruct them to re-add it asap. Thanks! -Wayne

Quotes source post: 12381430

Wayne, Thank you for jumping in and for sharing your revision with us. I will look at your tech articles again to see if the March update shows up - Hopefully before this weekend, which is when I will be performing the "operation". Regardless, your articles have been extremely helpful, and for that I am extremely grateful! Thank you!

Quotes source post: 12381430

Hi Wayne, thanks for the update and it's good to see the note. I don't know what others had assumed but one example I read was the comment by "sisco" on 3/18/15 here. He claimed he followed the instruction to the letter and his timing shifted. Nick from Pelican replied to him. http://www.pelicanparts.com/techarti...MS_Bearing.htm

I hate to revive a probably already hammered thread but please have patience in the following newbie question. I am planning to replace the IMS flange to repair a slow leak from that area on my 06 C2S. For this procedure do I need to lock the cams since I am only replacing the flange and not touching the IMSB? (Of course I wouldnt be able to replace the IMSB without splitting engine open anyway Thanks in advance!

Quotes source post: 12462652

Definitely, plus you also need to remove the bank 1 chain tensioner and the IMS chain tensioner. Both on the flywheel side. You may also want to consider removing the outer seal of the IMSB while you are there.

Personally I don't think it's necessary to lock the cams or remove the chain tensioner. I just successfully completed the IMS bearing replacement myself and learned that the bearing fits inside the shaft. Based on that, my thought is that I don't see how anything could shift by simply replacing the flange. You do, however, need to be careful not to mess up the bolt that goes in from the inside of the bearing - otherwise you'll be performing an IMS bearing replacement, meaning that you WOULD need to lock the cams and drop the tensioners. You might get conflicting answers on this - I'm just using my personal opinion on this...Good luck!

Quotes source post: 12467871

You must not have seen those "Help! My IMS is not centered!" threads Usually go like this "Did you turn crank to TDC cyl#, lock the cams and remove the two tensioners before you remove the flange?" "Oops....no. Are you supposed to?"

If you didn't pull any tensioners, lock any cams, or even put the engine at TDC before removing the IMSB flange, and you didn't jump time, and were able to R&R the IMSB, you better go play the lottery. You better go play it right now. the reason things can shift is the IMSB flange centers the IMSB and carries loads from the IMS tensioner paddle (placed directly onto the IMS main drive chain) as well as the valve spring loads from bank 1 valve train. Anytime a flange is to be removed, you must treat the procedure exactly the same as an IMSR process. If not, you'll pay for it. 3 chain engines are especially critical, they have very little chain wrap onto the exhaust cam sprocket.

I won't be playing the lotto. I'm not THAT lucky. I have to clarify that I did lock the cams at TDC and I removed the tensioners as instructed when I replaced my IMS bearing. I just didn't realize that procedure would also be required to simply replace the flange. I guess I was wrong about that. Sorry folks...